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Hints on how to restore your own recordings

Turntable selection

If you only play 33rpm and 45rpm records, your current turntable should work fine, provided it is properly aligned for stylus (needle) angle, pressure and anti-skating.
If not, channel separation, balance and phasing will be affected.

Check your turntable specifications for rumble. Good turntables have low rumble. (-75db) Poor turntables have more. (-65db)

The Technics SL-1200 series turntables have very good rumble specifications, (-79db) and are widely available. Ebay has lots of them. The SL-Dx series uses many of the same parts and are less expensive. Stay away from cheap turntables that try to look like the Technics SL-1200, but have poor rumble specs.

To play 78rpm records, you need a larger stylus for your cartridge since the grooves are bigger. Most turntables do not play 78rpm records, so you may need another turntable.
Also, your turntable must have a variable speed control, as some 78rpm records were not recorded at exactly 78rpm and can range from 60 to 90rpm.
Styli for 78rpm records are available for a small number of cartridges, so you may need to replace your cartridge as well.

Also, some 78 records, particularly the homemade ones (like the Victor home recording records) used a larger stulus than the standard 78. Playing these records with the standard stylus will make for a very noisy recording.

Phono preamp selection

Purchase a high-end phono preamp (such as the Derumbleizer), since your average phono preamp commonly available will reduce the high frequencies (make your music sound muddy) due to loading of the preamp output circuit.

The preamp must have settings to vary the capacitance loading of the turntable cartridge (the Derumbleizer does), if it does not the high treble will be either muddy or shrill, since different turntable cartridges require different values of capacitance loading, and the loading capacitance affects frequency response.
The capacitance of the RCA cables will also have to be taken into consideration. A test record can be used to help adjust the capacitance loading setting.

Expect to pay at least $150 for a good preamp with RIAA equalization. (red line)


You will pay from $300 to $2000 for a preamp with variable equalization settings, (blue lines) required to play older records, as the RIAA equalization curve was standardized only in the 1950s.
No equalization at all (purple line) was used on very old acoustically recorded discs.

Listen to a Bob Hope transcription record played back using the correct equalization,
and using the wrong equalization (RIAA).
Note the boomy bass and missing highs in the RIAA playback.

Hooking everything up

If you use your stereo to preamplify your turntable, does it have a high-end preamp built in, or is it an average preamp?
You may be suprised at how many "hifi" manufacturers cut corners and use average circuitry.

Be mindful of cable lengths and ground loops, which introduce noise and hum into your recordings.
Keep cables under 6 feet in length and plug the computer into the same wall outlet as the stereo.

Sound card selection

Buy the best sound card you can afford. Quality sound cards are almost never in your local computer store. They're hard to find and are priced accordingly: up to thousands of dollars. Make sure the sound card is designed to RECORD audio in stereo, all else is fluff. Turtle Beach and M-Audio make some very good sound cards, and the Event series are excellent.

Again, check specifications. Look for low noise, low jitter, high separation, high dynamic range, high sound to noise ratio, wide frequency response, and low distortion.
It doesn't matter that the sound card can playback into 47 speakers in ultra-wide-pseudo-acoustic-frammis mode if it has more jitter than a paranoid chihuahua after a triple-shot cappuccino.

Cheap sound cards actually introduce noise into the recording and playback of your audio files. Some have sound-to-noise ratios little better than cassette decks!

Never use an on-board sound card. They are always worse than sound cards that are added into your computer.

Audio restoration software selection

Purchase software (and/or hardware) necessary to do actual processing of your audio files.
Programs (and software/hardware combinations) range in price from free to thousands of dollars, and vary widely in performance and ease of use. Many software packages can be downloaded and used in a trial versions for a period of time at no cost. You may have to try dozens of "solutions" to find the one that works for you.

Make sure the software doesn't mangle the audio when running some processes, some programs do. Try every filter with records and tapes to see how they perform.

Some programs have live previews of filters. (handy, but not essential) These features require a fast computer to work properly. Make sure the program has a Batch Processing mode. That enables you to set the program up to process a bunch of audio files overnight, without having to sit there and babysit the computer.

Learn your software

Spend some time learning how your software works, since restoring audio is not a plug-and-play affair. Adjustments are necessary and any good software package has dozens of choices as to what to do with the audio files. Make sure the software has easy to understand Help files, preferably with examples.

Practice, practice, practice! Learn which filters to apply first, and which later. Some filters can affect other filters you use later on. For example, don't apply any low pass filtering before click and pop removal. The low pass filter will remove the ability for the software to detect the clicks and remove them.

Playing tapes

Purchase a tape deck and use it for playing only. Have the tools available to adjust the playback heads and adjust them for each tape you play. If you want to use the tape deck for recording, you must have a tape head alignment tape to do that. This applies to cassette, reel to reel and 8-track tape players, as well as microcassette, Elcaset and DCC too.

Alignment tools

Tools needed for alignment are:

And optionally

Doing the CD transfer

Use premium gold or silver/silver CDRs. These use the longer lasting phthalocyanine dye and are estimated to last 100 years. The green and blue dyes have been tested and don't last as long. Also, some people say that burning CDRs at high speed results in more bit errors on the CD than burning at slower speeds, but conclusive evidence wasn't found to back up that claim. We burn at 24x maximun just in case.

Write directly on the CD with a felt tip marker, or use an ink jet printer to print directly on the CD itself. Don't use self adhesive paper labels, because they can peel off or jam in some CD players. Never write on a CD with a ball point pen. That can deform the reflective layer and make the CD unaplayable.

If you have a bad CD, you can perform an experiment. Press your fingernail against the label side and look for the impression on the other side. That's because the clear plastic is thick on one side, and it's very thin on the other.

All modern CD players are able to play CDR discs, but a small number of older CD players may not be able to.

Precision Audio Restoration has done all this work for you, so your recordings can sound "better than new".

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Mail recordings to:
Precision Audio Restoration
14419 Greenwood Ave. N., Suite A, Box 321
Seattle, WA 98133
Call 206-387-5662 or email to receive
directions to drop off recordings personally.
By appointment only.

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